AMERICAN INSTITUTE. 617 



lapon the engine, it becomes uncontrolled by the engineer, doing 

 much damage to the machinery before it can be stopped. 



Cannot some arrangement be made, whereby the engineer may 

 pack his piston, without removing the cylinder head, and going 

 through various other performances. 



The present arrangement of slide valves on the steam chest is 

 bad, from the fact that they are not well balanced, and conse- 

 quently do not work steam tight. 



• When there are two engines in a vessel, can any arrangement 

 be made, whereby the power can be transmitted equally for driv- 

 ing two shafts with uniform speed, of course supposing an equal 

 resistance to each ? 



Formerly a jacket was made use of to encircle the cylinder with 

 steam. Why was it abandoned 1 Why do the English now give 

 preference to the single horizontal cylinder engine, instead of the 

 double vertical cylinder engine? Formerly the wear of the 

 piston upon the lower side of the cylinder of the horizontal engine 

 was unequal; that is not the case now, as they are precisely 

 made. 



Why may not steam be used as a brake on railroad locomotives, 

 by some arrangement in the cylinder, supplying it above or be- 

 low, on the exhausted side, or vice versa — thus suspending the 

 movement at once ■? 



An engine has been invented by Beaumont, for producing heat 

 sufficient to generate steam, capable of application to practical 

 purposes by friction,- The construction thus: a boiler is made, 

 traversed by a conical tube of copper, 30 inches diameter at the 

 top, 35 inches at the bottom, inside of which a cone of wood of 

 the same shape is fitted, enveloped in a padding of hemp. An 

 oil vessel keeps the hemp continually lubricated, and the wooden 

 cone is so constructed as to press steadily against the inside of the 

 copper, and to rotate rapidly by means of a crank turned by 

 power. The whole of the boiler outside of the copper is filled 

 with water. 



Thus constructed, the machine with four hundred revolutions 

 a minute, makes four hundred litres (or quarts) of water boil in 

 about three hours, by the mere effect of the friction of the oiled 

 tow against the copper. When once the boiling point is reached, 

 it may be maintained for any length of time, or as long as the 

 movement is continued. 



Mr. Tillman had paid sufficient attention to this friction tlieory. 

 Count Mumford, you know, attempted it, but I have entirely 

 given it up, long ago. 



